Heat water and kombu until just about to boil, turn off heat, and remove kombu. Place shiitakes in water and let soak for 20-30 minutes. Remove and discard stems, and set the mushrooms aside. Add sake, soy sauce, and mirin to the soaking water to make “dashi.”

Place kombu in center of large pan and place the eggs on top. Arrange the tofu, carrots, turnips, and shiitakes around the eggs.

Pour in the dashi, and heat until it just starts to boil. Partially cover and simmer for 30 minutes. Remove from heat, uncover, and let sit for 15 minutes. Refrigerate for 2 hours or even overnight.

When ready to serve, bring to a simmer, cover, and cook for 2 minutes. Place scallions on top and cook another minute. Add spinach and cook another minute, then add watercress, cover, and remove from heat. Let sit for a minute, then transfer to serving bowls, with a halved egg on top of each bowl topped with mustard.

Notes

Adapted from The Moosewood Collective’s Sundays at Moosewood Restaurant: Ethnic and regional recipes from the cooks at the legendary restaurant.